Background: Asthma morbidity and mortality are higher
in the United States for African-American (AA) children when compared
to European-American (EA) children.
To explore racial differences in physiologic factors associated with
pediatric asthma severity.
Methods: We analyzed data from
two groups of children in suburban Detroit, one of which contains
non-urban, middle-class AA children, a group not usually included in
childhood asthma studies. All children were 6 to 8 years of age.
Clinical evaluations included medical history, physical examination,
skin testing, spirometry, and methacholine challenge.
Results: The study population (n = 569) was 14% African
American, 51% of the participants were male, and the mean age was
6.8 ± 0.4 years. Socioeconomic status (parental education) was
similar overall by race, although some strata-specific differences were
observed. The prevalence of physician-diagnosed asthma was 10% for
both AA and EA groups. AA children were more reactive to methacholine
than EA children (42% vs 22%, respectively; p = 0.001), and had
significantly higher total IgE than EA children (geometric mean, 60.6
vs 27.5 IU/mL; p = 0.001). Serum IgE was related to methacholine
reactivity in EA children (p = 0.001), but not AA children
(p = 0.73). These differences remained after adjustment for gender,
age, parental education, parental smoking, and maternal smoking during
Conclusions: Our data support previous
reports of racial differences in lung volume, airway responsiveness,
and serum IgE concentrations. We found a racial difference in the
relationship between total serum IgE and airway responsiveness that is
unreported elsewhere. Overall, our results suggest that AA children may
be predisposed to asthma.